That conclusion applies to just one of America's 16 medical marijuana states. But it seems to speak volumes.

Esther Choo, an emergency doctor at Rhode Island Hospital, took a look at 32,570 teens in Rhode Island, where medical marijuana was made legal in 2006. For comparison they looked at usage dating back to 1997.

Choo:

Our study did not find increases in adolescent marijuana use related to Rhode Island's 2006 legalization of medical marijuana; however, additional research may follow future trends as medical marijuana in Rhode Island and other states becomes more widely used.

Makes sense. Despite the Starbucks-like retail environment for pot in L.A., dispensaries here are pretty strict about age limits.

Dennis Romero has worked on staff at several magazines and newspapers, including the Philadelphia Inquirer and the Los Angeles Times, where he participated in Pulitzer Prize-winning coverage of the L.A. riots. His work has appeared in Rolling Stone online, the Guardian, and, as a
young stringer, the New York Times.